The present invention relates to reflector structures as applied to at least one light emitting surface of semiconductor electroluminescent devices, such as, injection lasers or light emitting diodes (LEDs).
Heretofore, the suggestion has been made to apply multilayered structures to at least one facet surface of an electroluminescent device to provide a high level of reflectivity. If the reflectivity level is high at one of the facet surfaces, the current threshold of the device is reduced because more of the optical radiation is reflected back into optical radiation cavity of the device. Such multilayered reflector structures are disclosed in U.S. Pat. Nos. 4,092,659 and 4,147,409.
The prior art multilayered reflector structures require several layers of materials to provide high levels of reflectivity. For example, U.S. Pat. No. 4,092,659 discloses a stack reflector that requires four contiguous layers to provide a high level of reflectivity.
What is proposed here is a three layer reflector that will provide a reflector structure that has relatively high modal reflectivity.